The iPhone that Snowden is alluding to is the iPhone 5C that belonged to one of the suspects of the mass shooting in San Bernardino in December 2015. A judge ordered Apple to unlock the phone in February 2016. Apple very publicly refused to comply.

The FBI ultimately withdrew the case against Apple after finding a third party to gain access into the iPhone. But the FBI has yet to reveal to the public how this third-party entity accessed the phone, stoking fears that it could be found out and exploited by others — such as hackers or foreign governments. It's unclear, however, if the FBI has contacted Apple through private channels to reveal how the hack was performed.